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🔒 SSL Certificate Checker

Verify, decode, and inspect SSL/TLS certificates of any website. Ensure your connection is secure and get detailed certificate information.

🔍 Enter Domain

Enter a domain and click "Check Certificate".

📜 Certificate Details

Subject
-
Issuer
-
Valid From: -
Valid Until: -
Days Left: -
Status: -
Serial #: -
Algorithm: -

📋 How to Use SSL Certificate Checker

1

Enter Website URL

Type the full domain name (e.g., example.com) or complete URL (https://example.com) into the input field.

2

Click "Check Certificate"

The tool fetches the certificate directly from the website's server and analyzes it.

3

Review Details

See subject, issuer, validity period, and status. Check if the certificate is valid, expired, or invalid.

4

Interpret Results

Use the "Days Left" to know when it expires. A valid certificate ensures encrypted communication.

❓ Frequently Asked Questions

▶ What is an SSL certificate?
An SSL (Secure Sockets Layer) certificate is a digital certificate that authenticates a website's identity and enables an encrypted connection. It ensures that all data passed between the web server and browser remains private and integral. It's essential for e-commerce, logins, and any site handling sensitive data.
▶ How do I check if a website has a valid SSL certificate?
You can use this tool! Simply enter the domain name. The tool will fetch the certificate and display its details. Look for the "Status" field: it should show "Valid" and the "Valid Until" date should be in the future. Also, check the "Days Left" to see how soon it expires.
▶ What do the different certificate statuses mean?

Valid: The certificate is active, trusted (usually), and not expired.

Expired: The certificate's validity period has ended. Browsers will show security warnings.

Invalid: The certificate could not be retrieved or verified (e.g., domain doesn't exist, connection issue, or self-signed).

Expiring Soon: The certificate is still valid but has less than 30 days left. It's time to renew.

▶ Why does it show "Certificate Mismatch"?
This error occurs when the certificate's Common Name (CN) or Subject Alternative Names (SANs) do not match the domain you entered. For example, a certificate issued for "example.com" will not be valid for "google.com". It's a common security check to prevent impersonation.
▶ Can I check certificates on non-standard ports?
This basic checker uses the standard HTTPS port (443). Most websites use this. For ports like 8443, you'd need a more advanced tool. However, for the vast majority of public websites, this checker will work correctly.
▶ What is the difference between "Subject" and "Issuer"?
Subject is the entity the certificate is issued to, typically your website's owner. Issuer is the Certificate Authority (CA) that validated and signed the certificate, like Let's Encrypt, DigiCert, or Sectigo. The issuer's root certificate is usually trusted by your browser/OS.